The detection of volatile organic compounds (VOCs) and humidity has many commercial, public, and residential applications due to environmental and safety concerns. One useful sensor type is a capacitive sensor in which a sorbent material is disposed between two electrodes. Typically, at least one of the electrodes is porous or otherwise permeable by the analyte vapor to be measured. Examples of sorbent materials used in these types of sensors include so-called Polymers of Intrinsic Microporosity (PIMs, for VOC measurement) and sulfonated fluoropolymers (for humidity measurement).
Most commercially available organic vapor sensor systems are based on the Photo-Ionization Detector (PID) technology. Even though PID sensing technology is common, it has its limitations, such as large size, high cost, and high power consumption. For applications wherein ambient air quality is of concern (e.g., in a factory or other workplace), portability is highly desirable. Ease of operation, ease of maintenance, and cost are also important concerns. There is a continuing need for new organic vapor sensor systems that provide improvement relative to at least one of the above-mentioned problems.